Adrenergic stimulation modulates cardiac function by altering the phosphorylation status of several cardiac proteins. The Troponin complex, which is the Ca2+ sensor for cardiac contraction, is a hot spot for adrenergic phosphorylation. While the effect of β-adrenergic related PKA phosphorylation of troponin I at Ser23/24 is well established, the effects of α-adrenergic induced PKC phosphorylation on multiple sites of TnI (Ser43/45, Thr144) and TnT (Thr194, Ser198, Thr203 and Thr284) are much less clear. By utilizing an IAANS labeled fluorescent troponin C, , we systematically examined the site specific effects of PKC phosphomimetic mutants of TnI and TnT on TnC’s Ca2+ binding properties in the Tn complex and reconstituted thin filament. The majority of the phosphomemetics had little effect on the Ca2+ binding properties of the isolated Tn complex. However, when incorporated into the thin filament, the phosphomimetics typically altered thin filament Ca2+ sensitivity in a way consistent with their respective effects on Ca2+ sensitivity of skinned muscle preparations. The altered Ca2+ sensitivity could be generally explained by a change in Ca2+ dissociation rates. Within TnI, phosphomimetic Asp and Glu did not always behave similar, nor were Ala mutations (used to mimic non-phosphorylatable states) benign to Ca2+ binding. Our results suggest that Troponin may act as a hub on the thin filament, sensing physiological stimuli to modulate the contractile performance of the heart.